1. Field of Invention
This invention relates to the treatment of water and, in particular, to a treatment for removal of scale deposits and heavy metal salts from any vessel in which water is stored, e.g., a pool or spa or cooling tower.
2. Brief Statement of the Prior Art
Scale is commonly formed on pools, spas, cooling towers and other confined containers of bodies of water in which the total hardness of the water increases with evaporation, resulting in the precipitation of hardness from the water as scale deposits, typically calcium carbonate.
The problem is most noticeable and objectionable in swimming pools and spas because of the unsightly appearance of the scale deposits. The problem, however, is nonetheless present in other applications such as in cooling towers where the scale deposits can clog equipment and interfere with efficient operation.
A common technique for the removal of the deposits has been to drain the water completely from the pool and treat the pool surfaces with various agents. Acids are used for this application, however, the pool industry generally recommends against the use of acid treatments. The danger is that the acid will damage equipment or severely pit or erode plaster surfaces of pools. When acids are used, caution must be exercised to avoid damaging the pool surfaces and to avoid injury to the workmen. The potential for injuries increases when treating indoor pools because of the toxic nature of the acid fumes generated during the treatment. Accordingly, the acid washing of pools to remove scale deposits is practiced only by skilled professionals and is generally not recommended for swimming pool treatment, and particularly not recommended to be practiced by the pool owner.